How to use Epson POS printer TM-T20II under linux

Posted on April 17, 2019 by manuel

Getting an epson pos printer up and running under linux is very easy:

# add current user to lp group (requires relogin to work properly)
sudo usermod -a -G lp $USER

# for TM-T20II add udev rule (optional in my case):
echo 'SUBSYSTEM=="usb", ATTRS{idVendor}=="04b8", ATTRS{idProduct}=="0e15", MODE="0664", GROUP="lp"' > sudo tee -a /etc/udev/rules.d/99-escpos.rules
sudo service udev restart

# install pip and pipenv
sudo apt install python-pip
pip install --user pipenv

# install download python-escpos and submodules
git clone https://github.com/python-escpos/python-escpos.git
cd python-escpo
git submodule update --init --recursive

# install including deps
pipenv install -e .

Now you should be ready to use the installation. From your installation repository run a pipenv shell by using “pipenv shell” or simply run “pipenv run python _your-script_.py” to run a script directly.

Here is an example script:

from escpos.printer import Usb

# see https://github.com/python-escpos/python-escpos/blob/development/src/escpos/escpos.py

""" Seiko Epson Corp. Receipt Printer (EPSON TM-T20II) """
p = Usb(0x04b8, 0x0e15, 0, profile="TM-T88II")

p.set(bold=True, underline=1, align='center', custom_size=True, width=2, height=2)
p.textln("Hello world")
p.ln(count=1)
p.set()
p.textln("this is a test")

p.set(align='center')
p.image("examples/graphics/climacons/rain.png")
p.qr("Dies ist ein Test", size=8)
p.set()

p.barcode('1324354657687', 'EAN13', width=3)
p.barcode('123456', 'CODE39', width=3)

p.block_text("Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.", font='a', columns=None)

p.cut()

redis-server on ubuntu 18.04

Posted on March 30, 2019 by manuel

After installing redis on my machine I received the following error message:

redis-server.service: Can’t open PID file /var/run/redis/redis-server.pid (yet?) after start: No such file or directory

This message comes because redis refuses to start with disabled ipv6. To get it running you have to remove “::1” from “bind 127.0.0.1 ::1” in /etc/redis/redis.conf. Then redis starts as expected.

Add charles certificate to JVM

Posted on September 15, 2018 by manuel

This is an example how to do that on a Mac:

sudo keytool -import -noprompt -alias charles-$(date +%Y%m%d%H%M%S) -file "Downloads/charles-ssl-proxying-certificate.pem" -keystore "/Library/Java/JavaVirtualMachines/jdk-10.0.2.jdk/Contents/Home/lib/security/cacerts" -storepass changeit

1	sudo keytool -import -noprompt -alias charles-$(date +%Y%m%d%H%M%S) -file "Downloads/charles-ssl-proxying-certificate.pem" -keystore "/Library/Java/JavaVirtualMachines/jdk-10.0.2.jdk/Contents/Home/lib/security/cacerts" -storepass changeit

Add charles ssl proxy certificates to JDK on a mac

Posted on September 4, 2018 by manuel

First you need to run charles and enable SSL proxying. The see which JDK is used by your application and add the certificate to the cacerts file:

curl -s http://ssl.charles/ --proxy 127.0.0.1:8888 > cert_file
sudo keytool -import -noprompt -alias charles-$(date +%Y%m%d%H%M%S) \
  -file cert_file \
  -keystore /Library/Java/JavaVirtualMachines/jdk-10.0.2.jdk/Contents/Home/lib/security/cacerts \
  -storepass changeit
rm cert_file

curl -s http://ssl.charles/ --proxy 127.0.0.1:8888 > cert_file

sudo keytool -import -noprompt -alias charles-$(date +%Y%m%d%H%M%S) \

-file cert_file \

-keystore /Library/Java/JavaVirtualMachines/jdk-10.0.2.jdk/Contents/Home/lib/security/cacerts \

-storepass changeit

rm cert_file

Access Ubuntu 18.04 via VNC from Mac

Posted on June 15, 2018 by manuel

Ubuntu

First prepare the ubuntu machine by installing vino:

sudo apt install vino

1	sudo apt install vino

Then hit windows button and look for sharing. Configure the system to allow remote connections with given password.

You also need to disable encryption with:

gsettings set org.gnome.Vino require-encryption false

1	gsettings set org.gnome.Vino require-encryption false

MAC

Then you can access the machine from your Mac with Screen Sharing app with the url

vnc://<IP>:5900

1	vnc://<IP>:5900

Add network bridge with ubuntu 18.04

Posted on June 14, 2018 by manuel

To create a network bridge with netplan you have to create a file

network:
  version: 2
  ethernets:
     enp6s0:
        dhcp4: true
  bridges:
     br0:
       interfaces: [enp6s0]
       dhcp4: true
       optional: false
       macaddress: <some mac>

network:

version: 2

ethernets:

enp6s0:

dhcp4: true

bridges:

br0:

interfaces: [enp6s0]

dhcp4: true

optional: false

macaddress: <some mac>

Make sure to place a mac address in and replace the interface name enp6s0 with yours.

Then run sudo netplan apply.

The machine gets a new IP from dhcp so make sure you have it configured in your dhcp before or have a local console 😉

run kong with compose

Posted on December 29, 2017 by manuel

Here a simple docker-compose.yml file to get kong community up and running. It is configured to use postgresql that persists data to a local docker volume. All ports are mapped to localhost only and log goes to stdout/stderr.

version: '3.4'
services:
  kong-db:
    image: 'postgres:10.1'
    ports:
      - 127.0.0.1:5432:5432
    environment:
      POSTGRES_USER: kong
      POSTGRES_PASSWORD: kong
      POSTGRES_DB: kong
      PGDATA: /var/lib/postgresql/data/pgdata
    volumes:
      - db-volume:/var/lib/postgresql/data/pgdata
    healthcheck:
      test: 'echo "select 1" | psql -U kong kong || exit 1'
      interval: 1m
      timeout: 3s
      retries: 3
    restart: unless-stopped

  kong:
    image: 'kong:0.11.2'
    ports:
      - 127.0.0.1:8000:8000
      - 127.0.0.1:8443:8443
      - 127.0.0.1:8001:8001
      - 127.0.0.1:8444:8444
    environment:
      KONG_DATABASE: postgres
      KONG_PG_HOST: kong-db
      KONG_PG_DATABASE: kong
      KONG_PG_USER: kong
      KONG_PG_PASSWORD: kong
      KONG_PROXY_ACCESS_LOG: /dev/stdout
      KONG_ADMIN_ACCESS_LOG: /dev/stdout
      KONG_PROXY_ERROR_LOG: /dev/stderr
      KONG_ADMIN_ERROR_LOG: /dev/stderr
    links:
      - kong-db
# uncomment following line to run migrations for a new database
#    command: kong migrations up -v
    depends_on:
      - kong-db
    healthcheck:
      test: 'curl -f http://localhost:8001/status || exit 1'
      interval: 1m
      timeout: 3s
      retries: 3
    restart: unless-stopped

volumes:
  db-volume:

version: '3.4'

services:

kong-db:

image: 'postgres:10.1'

ports:

- 127.0.0.1:5432:5432

environment:

POSTGRES_USER: kong

POSTGRES_PASSWORD: kong

POSTGRES_DB: kong

PGDATA: /var/lib/postgresql/data/pgdata

volumes:

- db-volume:/var/lib/postgresql/data/pgdata

healthcheck:

test: 'echo "select 1" | psql -U kong kong || exit 1'

interval: 1m

timeout: 3s

retries: 3

restart: unless-stopped

kong:

image: 'kong:0.11.2'

ports:

- 127.0.0.1:8000:8000

- 127.0.0.1:8443:8443

- 127.0.0.1:8001:8001

- 127.0.0.1:8444:8444

environment:

KONG_DATABASE: postgres

KONG_PG_HOST: kong-db

KONG_PG_DATABASE: kong

KONG_PG_USER: kong

KONG_PG_PASSWORD: kong

KONG_PROXY_ACCESS_LOG: /dev/stdout

KONG_ADMIN_ACCESS_LOG: /dev/stdout

KONG_PROXY_ERROR_LOG: /dev/stderr

KONG_ADMIN_ERROR_LOG: /dev/stderr

links:

- kong-db

# uncomment following line to run migrations for a new database

# command: kong migrations up -v

depends_on:

- kong-db

healthcheck:

test: 'curl -f http://localhost:8001/status || exit 1'

interval: 1m

timeout: 3s

retries: 3

restart: unless-stopped

volumes:

db-volume:

Attention: The kong container fails to start unless migrations are not run on the connected database. To do this simply uncomment the marked line and start the containers. With the command set the container will execute database migrations and stop with exit code 0. After that the line can be commented out again. Then you can start kong with the given file.

IntelliJ IDEA on Mac OS

Posted on October 29, 2017 by manuel

When using IntelliJ IDEA with Spring Boot on a Mac make sure you have the entry

127.0.0.1 <hostname>.local

1	127.0.0.1 <hostname>.local

in your /etc/hosts file. Replace <hostname> with your Mac’s name. Also make sure that the result of the command ‘hostname’ is in your /etc/hosts file as well pointing to your local address.

Java 9 released

Posted on September 23, 2017 by manuel

After years of development Oracle has released Java 9. It is available to download from the Oracle page as usual. Here is the EOL message for Java 8:

End of Public Updates for Oracle JDK 8

Oracle will not post further updates of Java SE 8 to its public download sites for commercial use after September 2018. Customers who need continued access to critical bug fixes and security fixes as well as general maintenance for Java SE 8 or previous versions can get long term support through Oracle Java SE Advanced, Oracle Java SE Advanced Desktop, or Oracle Java SE Suite. For more information, and details on how to receive longer term support for Oracle JDK 8, please see the Oracle Java SE Support Roadmap.

Openssl certificates for apache

Posted on September 20, 2017 by manuel

In my former post i described a way how to create self signed SSL certificates with an own certificate authority. These certificates didn’t work in latest chrome versions so I updated my scripts to create valid certificates for chrome. This time I only create wildcard certificates because creating one for every subdomain was annoying.

#!/bin/bash
if [ -e ca.key ]; then
	echo "ca.key already exists"
	exit 1
fi

openssl genrsa -out ca.key 4096
openssl req -new -x509 -days 3650 -key ca.key -out ca.crt \
  -subj "/C=AT/ST=Vienna/L=Vienna/O=Coffeebeans/CN=Coffeebeans Domain Validation Secure Server CA/emailAddress=office@coffeebeans.at"

#!/bin/bash

if [ -e ca.key ]; then

echo "ca.key already exists"

exit 1

openssl genrsa -out ca.key 4096

openssl req -new -x509 -days 3650 -key ca.key -out ca.crt \

-subj "/C=AT/ST=Vienna/L=Vienna/O=Coffeebeans/CN=Coffeebeans Domain Validation Secure Server CA/emailAddress=office@coffeebeans.at"

#!/bin/bash
NAME=star.$1
if [ "star." == $NAME ]; then
	echo "usage: $0 <domain.name>"
	exit 1
fi
if [ -e $NAME.key ]; then
	echo "$NAME.key already exists"
	exit 1
fi
if [ ! -e ca.crt ]; then
	echo "no ca certificate created"
	exit 1
fi

CONFIG=$(cat <<-EOF
[ca]
default_ca=CA_default

[CA_default]
dir=./ca
database=\$dir/index.txt
new_certs_dir=\$dir/newcerts
serial=\$dir/serial
private_key=./ca.key
certificate=./ca.crt
default_days=3650
default_md=sha256
policy=policy_anything
copy_extensions=copyall

[policy_anything]
countryName=optional
stateOrProvinceName=optional
localityName=optional
organizationName=optional
organizationalUnitName=optional
commonName=supplied
emailAddress=optional

[req]
default_bits=4096
prompt=no
default_md=sha256
req_extensions=req_ext
distinguished_name=dn
 
[ dn ]
C=AT
ST=Vienna
L=Vienna
OU=Domain Control Validated
emailAddress=office@coffeebeans.at
CN=*.$1
 
[ req_ext ]
subjectAltName=@alt_names
 
[ alt_names ]
DNS.1=$1
DNS.2=*.$1
EOF
)

# PREPARE
echo "$CONFIG" > config.txt
if [ ! -d ./ca ]; then
	mkdir -p ./ca/newcerts
	touch ./ca/index.txt
fi

openssl genrsa -out $NAME.key 4096
openssl req -new -key $NAME.key -out $NAME.csr -config config.txt
openssl ca -create_serial -batch -in $NAME.csr -out $NAME.crt -config config.txt

# CLEANUP
rm -f *.csr config.txt
chmod 644 *.key *.crt

#!/bin/bash

NAME=star.$1

if [ "star." == $NAME ]; then

echo "usage: $0 <domain.name>"

exit 1

if [ -e $NAME.key ]; then

echo "$NAME.key already exists"

exit 1

if [ ! -e ca.crt ]; then

echo "no ca certificate created"

exit 1

CONFIG=$(cat <<-EOF

[ca]

default_ca=CA_default

[CA_default]

dir=./ca

database=\$dir/index.txt

new_certs_dir=\$dir/newcerts

serial=\$dir/serial

private_key=./ca.key

certificate=./ca.crt

default_days=3650

default_md=sha256

policy=policy_anything

copy_extensions=copyall

[policy_anything]

countryName=optional

stateOrProvinceName=optional

localityName=optional

organizationName=optional

organizationalUnitName=optional

commonName=supplied

emailAddress=optional

[req]

default_bits=4096

prompt=no

default_md=sha256

req_extensions=req_ext

distinguished_name=dn

[ dn ]

C=AT

ST=Vienna

L=Vienna

OU=Domain Control Validated

emailAddress=office@coffeebeans.at

CN=*.$1

[ req_ext ]

subjectAltName=@alt_names

[ alt_names ]

DNS.1=$1

DNS.2=*.$1

EOF

)

# PREPARE

echo "$CONFIG" > config.txt

if [ ! -d ./ca ]; then

mkdir -p ./ca/newcerts

touch ./ca/index.txt

openssl genrsa -out $NAME.key 4096

openssl req -new -key $NAME.key -out $NAME.csr -config config.txt

openssl ca -create_serial -batch -in $NAME.csr -out $NAME.crt -config config.txt

# CLEANUP

rm -f *.csr config.txt

chmod 644 *.key *.crt

I also tried to use these certificates in postfix which did NOT work. To create files for postfix see my former post.

Manuel's Cheat Sheet

Solutions to everyday IT problems

How to use Epson POS printer TM-T20II under linux

redis-server on ubuntu 18.04

Add charles certificate to JVM

Add charles ssl proxy certificates to JDK on a mac

Access Ubuntu 18.04 via VNC from Mac

Add network bridge with ubuntu 18.04

run kong with compose

IntelliJ IDEA on Mac OS

Java 9 released

Openssl certificates for apache